This invention relates to the manufacture of sanitary products such as tampons from an organic polymer foam.
Sanitary devices such as catamenial tampons have been prepared from organic polymeric foam. Such preparations usually entail the compression of the foam segment to a size suitable for insertion in the vagina and rely on various mechanical devices such as insertion tubes, for maintaining compression until insertion is completed. After insertion, the tubes are then withdrawn leaving the segment in position.
The above devices, however, possess several drawbacks. The foam segment, by virtue of its open-celled structure, is often abrasive and irritating to the vaginal membranes, which are particularly-sensitive during the menstrual period. The tampon assembly requiring the insertion tubes is cumbersome to carry and use, and consequently requires the presence of certain structural features, such as detents in both tubes to lock them in position before use, and lips or rings on the outer tube to assist in gripping during insertion. Such features are time-consuming to manufacture, and, thus, increase the cost of the final article.
In addition to the above assembly, tampons have been prepared which are mounted on insertion sticks, or are merely digitally insertable. These tampons, however, suffer from the same drawbacks and have, accordingly, been either coated or dipped with lubricants. It was found, however, that such lubricants tended to decrease the speed of absorption and absorptive capacity of the tampon, and correspondingly increase the incidence of menstural bypass.
A new class of foam materials has been discovered which yields foams possessing favorable hydrophilicity and improved expansivity. The foams comprise hydrophilic polyurethanes which are impregnated with from 10 to 200% of their weight, of a solid, water insoluble release agent which may be either an inorganic material, or a colloidal suspension of a solid organic material. These foams have been found to possess particular utility in catamenial devices, wherein they may be compressed to less than 50% of their original dry volume and placed in a constraining means, such as, for example, a gelatin capsule. The preparation of the foam containing the inorganic release agent is disclosed in the co-pending application of Louis L. Wood and Jerome L. Murray, Ser. No. 575,356, and the foam employing the organic release agent is disclosed in a co-pending application by Victor S. Frank and Jerome L. Murray, Ser. No. 575,348 both filed concurrently herewith, incorporated herein by reference.
A method for the preparation of sanitary products such as tampon devices has been developed by the Applicants herein for use with the above-referenced foams, which involves several particular operations, each employing an apparatus distinctly developed therefor. Such method and apparatus are the subject of co-pending application Ser. No. 575,200 incorporated herein by reference, and comprise the radial compression of a foam pre-form into a cylindrical die cavity of reduced diameter defined by three laterally reciprocable die faces in cooperation with a fourth stationary die face. The compressed pre-form is then axially compressed by a suitably disposed ram member and urged out of the die cavity and into a cavity defined in an adjacent base member provided with an open-ended container such as a gelatin capsule. The present apparatus and corresponding method constitute a specific embodiment of the above.